The present invention relates generally to a drill and drive apparatus, and more particularly to a drill and drive apparatus having an improved tool holder.
Throughout the years, various devices have been designed which allow an individual operating an electric drill to quickly change the tool being driven by the drill for another tool. For example, U.S. Pat. No. 4,573,839 (issued to Finnegan), discloses a drill and drive apparatus having a hollow main body portion which is adapted to receive a generally tube-shaped tool holder therein. The main body portion includes a shank which extends from the main body portion. The shank is secured to a chuck of the drill during use thereof. The tool holder is configured to releasably lock a drill bit within one of its ends using an alien screw, and lock a screwdriver bit within the other of its ends using another alien screw. The apparatus further includes a locking mechanism which operates to releasably lock the tool holder to the main body portion. During operation of the Finnegan apparatus, the tool holder may be secured partially within the main body portion while exposing the drill bit. Thereafter, the user may operate the apparatus to drill a hole in a workpiece. Then, the user may quickly release the tool holder from the main body portion, and rotate the tool holder 180xc2x0. Thereafter, the user may insert the rotated tool holder into the main body portion and then relock the tool holder thereto with the screwdriver bit exposed. Then, the user may place the tip of a threaded side of a screw in the hole located in the workpiece, and drive the screw into the workpiece with the drill and drive apparatus and the drill.
One drawback with the above-described drill and drive device is that changing the drill bit and/or the screwdriver bit by loosening and tightening the alien screws is a time consuming and cumbersome process. Consequently, other devices have been designed that include a quick connect locking mechanism which operates to releasably lock the drill bit and the screwdriver bit to the tool holder. For example, it is known to provide a locking mechanism for a tool holder of a chuck device wherein the locking mechanism includes a sliding sleeve disposed on the outside of the tool holder and releasably holding a ball in an annular retaining groove of a tool. The tool can be unlocked by sliding the sleeve relative to the remainder of the drive and drive apparatus in order to release the ball from the groove. After the tool is removed, a replacement tool can then be inserted, and the replacement tool is locked therein by sliding the sleeve back to its locked position to push the ball back into the groove of the replacement tool.
A drawback with quick connect designs of the above-described type is that the sliding sleeve that releasably holds the ball in the annular retaining groove is disposed on the outside of the tool holder, and thus adds to the outer diameter of the tool holder. It is advantageous for a tool holder to have a small diameter so that the tool holder can be inserted into narrow cavities. If the outer diameter of the tool holder is too large, it may prevent the tool holder from being inserted into narrow spaces in which it is desired to drill a screw hole, for example. From a structural integrity viewpoint, it is desirable for the walls of the tool holder to be as thick as possible in order to withstand the stresses resulting from the torquing of the tool during operation. However, from a functional viewpoint, it is desirable for the tool holder to be as thin as possible so that it can be inserted into narrow passageways to drill holes therein. For example, it may be desired to drill a screw hole at the bottom of a cylindrical cavity in a workpiece. If the diameter of the cavity is less than the diameter of the tool holder, then the tool holder cannot progress in the axial direction past the point where the tool holder contacts the workpiece at the top of the cavity. Since the drill bit is attached to the tool holder, the axial progression of the drill bit is also stopped once the tool holder has contacted the workpiece at the top of the cavity. Thus, it may not be possible for the drill bit held by the tool holder to reach the bottom of the cavity in order to drill a screw hole, or it may not be possible to drill the screw hole as deeply as desired.
What is needed therefore is a drill and drive assembly which overcomes one or more drawbacks of the previously designed devices. For example, what is needed is a drill and drive apparatus in which the drill bit and/or screwdriver bit can be quickly and easily removed from and replaced in the tool holder. Moreover, there is a need for a tool holder for a drill and drive apparatus that has a diameter small enough that the tool holder can be inserted into relatively narrow openings.
In accordance with one embodiment of the present invention, there is provided a drill and drive apparatus that includes a tube assembly which defines a tool chamber. The apparatus further includes a tool holder which is configured to be at least partially received in the tool chamber of the tube assembly. The tool holder includes a holder body defining a first tool recess and having (i) a first section with a first width and at least one ball aperture communicating with the first tool recess, and (ii) a second section with a second width less than the first width. The tool holder further includes a first tool locking mechanism at a first end portion thereof. The first tool locking mechanism includes (i) a tool locking collar positioned around the holder body and positionable between a tool lock position and a tool release position, (ii) at least one ball positioned with the at least one ball aperture, wherein the at least one ball extends into the first tool recess when the tool locking collar is positioned in the tool lock position, and the at least one ball can be located away from the first tool recess when the tool locking collar is positioned in the tool release position, and (iii) a tool spring, positioned around the second section of the holder body, which biases the tool locking collar toward the tool lock position.
Pursuant to another embodiment of the present invention, there is provided a tool holder for a drill and drive apparatus. The tool holder includes a holder body defining a first tool recess and having (i) a first section with a first width and at least one ball aperture communicating with the first tool recess, and (ii) a second section with a second width less than said first width. The tool holder further includes a first tool locking mechanism at a first end portion thereof, the first tool locking mechanism having a tool locking collar positioned around the holder body and positionable between a tool lock position and a tool release position, the tool locking collar including a back-up ring attached at an end thereof. The first tool locking mechanism also has at least one ball positioned within the at least one ball aperture, wherein the at least one ball extends into the first tool recess when the tool locking collar is positioned in the tool lock position, and the at least one ball is locatable away from the first tool recess when the tool locking collar is positioned in the tool release position. The first tool locking mechanism further has a tool spring, positioned around the second section of the holder body, which exerts force upon the back-up ring to thereby bias the tool locking collar toward the tool lock position.
According to still another embodiment of the present invention, there is provided a tool holder for a drill and drive apparatus. The tool holder includes a holder body defining a first tool recess and having (i) a first section with a first width and at least one ball aperture communicating with the first tool recess, and (ii) a second section with a second width less than said first width. The tool holder also includes a first tool locking mechanism at a first end portion thereof, the first tool locking mechanism having a tool locking collar positioned around the holder body and positionable between a tool lock position and a tool release position. The first tool locking mechanism also has at least one ball positioned within the at least one ball aperture, wherein the at least one ball extends into the first tool recess when the tool locking collar is positioned in the tool lock position, and the at least one ball can be located away from the first tool recess when the tool locking collar is positioned in the tool release position. The first tool locking mechanism further has a tool spring, positioned around the second section of the holder body, which biases the tool locking collar toward the tool lock position. The tool holder further includes a second tool locking mechanism at a second end portion thereof.
In another aspect of the invention, a tool holder for a drill and drive apparatus comprises a holder body defining a first tool recess open at a first end of the body to receive a tool therein. The holder body further includes (i) a first section adjacent the first end with a first outer dimension and at least one ball aperture extending therethrough in communication with the first tool recess, and (ii) a second section adjacent the first section and with a second outer dimension less than the first outer dimension. The apparatus further includes a first tool locking mechanism at the first end that includes a tool locking collar disposed around the first and second sections of the holder body. Together with the holder body the locking collar defines an annular chamber. The tool locking collar is slidable along the holder body between a tool lock position and a tool release position in which the annular chamber is disposed about the at least one ball aperture. The first tool locking mechanism further includes at least one ball disposed within theat least one ball aperture and movable within the aperture between a position extending into the first tool recess when the tool locking collar is positioned in the tool lock position, and a position located away from the first tool recess when the tool locking collar is in the tool release position. A biasing mechanism is disposed within the annular chamber that is operable to bias the tool locking collar toward the tool lock position.
It is one object of the present invention to provide an improved drill and drive apparatus. It is yet another object of the invention to provide a drill and drive apparatus in which a drill bit and/or a screwdriver bit can be quickly and easily removed from and replaced in a tool holder.
Yet another object is to provide a tool holder for a drill and drive apparatus that has a diameter small enough that the tool holder can be inserted into a relatively narrow space. Thus, the tool holder can be used to form pilot holes within cavities that are so narrow that it would not be possible to insert thicker tool holders into the cavities. Other objects and benefits of the present invention can be discerned from the following description and accompanying drawings.